Can genetics determine which children are at risk of sudden death? Sudden unexpected death in the young, which includes SIDS (Sudden Infant Death Syndrome), SUDEP (Sudden Unexpected Death in Epilepsy), and SUDC (Sudden Unexpected Death in Childhood), accounts for more deaths in the United States than all childhood cancers combined. The causes of death and how to identify those at risk remain largely unknown. Evidence suggests a biological link between SIDS, SUDEP, and SUDC. All display epilepsy-related defects in the hippocampus, a critical region of the brain involved in seizures, as well as a higher personal and familial rate of febrile seizures. The goal of this project is to find genes that underlie the hippocampal defects seen in each of these disorders, and thereby understand the biology of how SIDS, SUDEP, SUDC and febrile seizures are linked. This work may identify genetic and brain imaging biomarkers that can help determine who among children with febrile seizures, and their siblings, are at risk of death so that prevention strategies can be implemented.